Abstract

Background

Co-infection is frequently seen in critically ill patients with influenza, although the exact rate is unknown. We determined the rate of co-infection, the risk factors and the outcomes associated with co-infection in critically ill patients with influenza over a 7-year period in 148 Spanish intensive care units (ICUs).

Methods

This was a prospective, observational, multicentre study. Influenza was diagnosed using the polymerase chain reaction. Co-infection had to be confirmed using standard bacteriological tests. The primary endpoint of this analysis was the presence of community-acquired co-infection, with secondary endpoints including ICU, 28-day and hospital mortality.

Conclusions

Co-infection in critically ill patients with influenza has increased in recent years. In this Spanish cohort, age and immunosuppression were risk factors for co-infection, and co-infection was an independent risk factor for ICU, 28-day and hospital mortality.